Reasons Your AC Might Be Turning On and Off and How You Can Address Them
Published July 22, 2024 by Tony Spezza
You hear it kick on, then it quickly shuts off. On again, then off again, over and over….
If your AC keeps turning on and off, it’s not something you want to ignore.
Besides the fact that the air in your home will never cool down, you’ll see a rise in your electrical costs and may also be damaging your air conditioning system.
If you’re trying to determine why your AC keeps turning on and off, the professionals at AAA Heating and Cooling are here to help.
We talk about why short cycling happens in the first place, reasons your system may not be functioning properly, and how to address them to keep your home cool all season long.
Table of Contents
- If an AC Keeps Turning On and Off, Is It Short Cycling?
- Does an AC System That Keeps Turning On and Off Need To Be Replaced?
- 9 Reasons Your AC May Be Turning On and Off
- Can You Prevent Issues That Cause Your AC System To Turn On and Off?
- AAA Heating and Cooling: Your Trusted HVAC Professionals in the Greater Portland Area
If an AC Keeps Turning On and Off, Is It Short Cycling?
An air conditioner is short-cycling if it repeatedly turns on and off without ever completing a full cooling cycle.
This means your air conditioner will prematurely shut off the compressor and turn it back on again a short time later, repeating the process over and over.
When short cycling occurs, your air conditioner is basically locked into its start-up cycle. Not only is this a huge waste of energy, but it also runs your AC’s components, particularly the air compressor, through round after round of unnecessary stress.
It’s important to note, however, that when a system is turning on and off, it’s not *always* short cycling.
If you notice your AC keeps turning on and off or is acting strangely, it’s important to schedule a checkup. Family-owned for over 60 years, AAA Heating and Cooling is Portland’s trusted choice for all your HVAC needs. Contact us today to request an appointment.
The Importance of Determining the Reason an AC System Is Turning On and Off
When your AC keeps turning on and off, it not only wastes a ton of energy (and your hard-earned money), but it also puts your air conditioner’s parts under unnecessary stress. This is especially true of the unit’s compressor.
Addressing the issue quickly will help ensure there’s no permanent damage and that your unit is ready and able to keep your home feeling cool and comfortable.
Does an AC System That Keeps Turning On and Off Need To Be Replaced?
The answer to this question depends on why the unit keeps turning on and off and if it keeps happening after the issue is addressed.
There are a variety of possible reasons why your AC keeps turning on and off, including:
- Clogged air filter
- A damaged or faulty thermostat
- Compressor issues
- Dirty condenser coils
- Iced evaporator coils
- Leaking refrigerant
- An oversized system
- Drain line issues
- Problems with your electrical system
9 Reasons Your AC May Be Turning On and Off
#1: Clogged Air Filter
As your air conditioner cools the air in your home, it’s also filtering it, and it usually doesn’t taste long before your AC system’s filters become clogged and dirty. This can cause a variety of problems for the system since clogged filters can restrict the free flow of air to the unit and can easily lead to short cycling.
That’s why it’s important to regularly check your system’s air filters to see if they are dirty, and if necessary, replace them.
We recommend changing your AC’s air filters every 1–3 months when your unit is in peak use.
If your AC keeps turning on and off after replacing the air filter, it’s best to contact a reliable HVAC expert to check out the other AC components.
#2: Thermostat Issues
While it may appear to be a fairly insignificant part of your air conditioning unit, the thermostat is vital to the function of your system.
The reason your AC keeps turning on and off may be due to a thermostat that’s either broken or located in a spot not conducive to proper temperature readings.
If your thermostat isn’t working properly and fails to detect the correct temperature, it gives your air conditioner a false signal, telling it to repeatedly turn itself on and off.
If the screen on your thermostat is blank, the problem may be as easy to solve as simply replacing the battery. If this doesn’t resolve the issue, you’ll need an HVAC expert to examine the thermostat.
Your air conditioner issues may also result from a thermostat that’s in the wrong location to accurately take a temperature reading. Poor locations for thermostats generally include:
- In direct sunlight
- Under a window
- Near air vents
- Too close to rooms that heat up, such as a kitchen or bathroom
Usually, this problem can be solved by simply moving the thermostat to a more centralized location.
#3: A Damaged or Faulty Compressor
Your AC’s compressor is responsible for pushing evaporated refrigerant gas through your air conditioning unit to absorb heat. It also helps your air conditioner maintain a steady rhythm so it can consistently move heat out of your home.
Sometimes a compressor may become damaged, either by icing over or by liquid refrigerant making its way into the chamber.
Faulty AC compressors can easily malfunction and overheat. Not only can this cause your AC to keep turning on and off, but a defective compressor can cause other problems for your AC system and may make the other components wear out faster.
If you believe your compressor is the reason for your AC issues, you’ll need to contact a local HVAC professional to either remedy the problem or replace the compressor.
The team at AAA Heating and Cooling offers repair and maintenance services for residential and commercial air conditioners. We’re here to assist with any malfunction or general maintenance for your cooling system.
#4: Dirty Condenser Coils
Condenser coils take the heat from your home and release it into the outdoors. They can easily become covered in dirt, dust, and debris, which keeps the heat from escaping and can result in short-cycling or more serious problems.
If you discover it’s time for the condenser coils on your AC unit to be cleaned, a professional HVAC technician can help get your unit up and running properly again.
#5: Icing on the Evaporator Coils
Sometimes problems, like restricted airflow and refrigerant leaks, can make the evaporator coils on your AC system freeze up. When this happens, the unit turns off and on as the ice thaws and the system refreezes again.
If you notice ice buildup on your outdoor AC unit, contact your HVAC professional to diagnose and repair the air filter or refrigerant leak that’s causing the problem.
#6: Leaking Refrigerant
Refrigerants are coolants that circulate the flow of air from room to room.
Sometimes your air conditioner’s coolant system springs small leaks that allow refrigerant levels to become low. When this occurs, it can make your compressor malfunction and shut off because of low pressure.
As the pressure rises again, the compressor turns back on and then off as the refrigerant level lowers with this process repeating itself over and over. As your AC keeps turning on and off, your unit suffers a faster level of wear and tear and can potentially break down.
Refrigerant leaks don’t just cause problems for your air conditioning unit, but they can also cause potential hazards to humans. If you suspect this is the reason your AC keeps turning on and off, consult a reputable HVAC company to fix the leak ASAP.
#7: Oversized System
If you find your air conditioning system has never worked properly, it’s possible the unit might be too large for your space.
When this is the case, there’s a rapid and uneven refrigerant cycle that can lead to short cycling and other issues, including:
- High power bills
- Frequent repairs
- A shorter lifespan
A professional HVAC company can use an AC sizing calculator to perform a heat load calculation to determine if your AC is sized correctly.
#8: Drain Line Issues
It’s likely your air conditioning system has a “float switch” feature that turns the unit off when the water in the drain line fails to drain properly. However, if you switch your thermostat to “Auto,” and the air still doesn’t circulate, there’s a high possibility the drain line could be clogged.
In this case, you can attempt to drain the line on your own or contact an HVAC expert to help get it working properly.
#9: Faults in the Electrical System
An air conditioner that keeps turning on and off may also be the result of electrical problems. This could be due to a faulty:
- Capacitor
- Electric supply cable
- Circuit board
- Thermostat
Electrical issues in an air conditioning system can be tricky to diagnose, and even dangerous if you’re not a skilled electrician, so this is a time to call a professional HVAC company.
Can You Prevent Issues That Cause Your AC System To Turn On and Off?
The best way to prevent issues with your air conditioning unit is to have it serviced each year by a professional HVAC company like the team at AAA Heating and Cooling.
Portland has trusted us to provide residential air conditioners, products, and services to area families and businesses like yours since 1961, and we’d love to have the opportunity to serve you.
Contact us today to request an appointment.
AAA Heating and Cooling: Your Trusted HVAC Professionals in the Greater Portland Area
If your AC keeps turning on and off, let your first call be to AAA Heating and Cooling.
Our family-owned Portland business is dedicated to helping you with your HVAC needs by providing quality services, repairs, installations, and outstanding customer service.
As the leader in residential and commercial heating and air conditioning services in the Portland area for over half a century, AAA Heating and Cooling has provided thousands of clients with our expert services, including:
- Home heating services
- Home air conditioning services
- Commercial furnace services
- Commercial air conditioning services
- Duct cleaning
- And more
When you need HVAC services you can trust, call the experts at AAA Heating and Cooling.